I have aquired a Summit III pattern ship, YS .61 w/ pipe, retracts. I have never competed in pattern and don't know too much about it. I'd like to try it out, and I was wondering if this airplane would work for sportsman. I was also wondering if anyone had any good recommendations for prop sizes. I know this plane was not designed for the newer style pattern sequences, but I was hoping I could make it work long enough to see how I like pattern flying. I have flown the airplane with a 11x7.5 prop, but it doesn't seem like I'm getting enough performance. Any advise would be greatly appreciated. Thanks.

Bryan

Bryan,

First off, I highly recommend that you get in touch with other pattern fliers in GA. Emory Schroeter and Mike Hester are two good chaps to hook up with.

Second, the Summit III can be made to fly fairly slowly (assuming it was built true) and you could easily compete in Sportsman through Masters with it. I recommend you do the following to slow it down. Lengthen the pipe to approximately 15" to the high point of the pipe, measured from the glow plug, straight line. Then toss the toothpick prop and get a 12x11 or 12 or 13x10 or 11 APC. The engine will turn those props fine but you got to make sure the bearings are in good shape. As you turn the prop, you should not feel any gritty feel. It should be glass smooth.

If the bearing needs replacing, you can get one from Performance Specialties, or you could send the engine in for repair. On second though, send it in anyway so Richard can at least take a look at the regulator section and make any adjustments required. I used a K&B 1L plug on these engines burning 15% nitro fuel

Good luck

MattK

Bryan,
I have the prop's you need sitting in a box. You can have them. Send me a PM with your address and I'll ship them to you.
-Mark

Matt,

Thanks for the reply. I was told by the previous owner that the bearings had just been replaced, and in fact, they do feel very smooth. I'll check the pipe length when I get home. Thanks again.


Bryan

Oh yeah, I did not mention that the Summit III, an Ivan Kristensen design, Canada's most prolific aerobatic pilot and many time World Team participant, came in at near the end of the heavy "QUIET is BLISS" drive in pattern. The pipe settings I gave you were designed to quiet the models down, especially when coupled with a soft engine mount, but give nothing up in terms of performance. I hope your Summit has a soft mount in it

Engine rpms were down to around 10K give or take with the props I mentioned in the last post. The higher prop pitch produced the required speed and the lower rpm reduced noise to a "whisper". Well not really a whisper but compared to the small props we were turning at the kinds of rpms those engines were capable of (15K+ in the air) the new set-ups were very neighborhood friendly.

Regards,

MattK

Bryan,
I certainly agree with Matt on all accounts. First off, the Summit II is a terrific ship. Don't let anyone tell you different. 13x10 APC is probably a perfect fit provided you clear the pavement!

Joe W.

Bryan,
The props were shipped today. There were some 12x12N's(narrow), 13x9's, a 12.5x11 & 12x12 std. If you were using a plastic spinner; you may need to purchase a Tru-Turn FAI cut spinner and prop nut adaptor to fit these props. Central Hobbies should have what you need.
-Mark

Joe raises a good point about ground clearance. If the model has trike retracts, the larger diameter props could present a problem for grass fields.

MattK

The Summit 2 was one of my favorite planes of the day. It's only problem was that it lacked enough fin / rudder area and the nose would hunt . Ivan even made a mod to his Summit 2's tail and gave me a copy of the plans to convert mine. I'm sure the changes were incorporated into the Summit 3 even though I went into a 16 year retirement from pattern before the 3 came out.

That should be pretty hard on the Razors Edge isn't it?? I'm personally a bit more conservative than that...

I was tuning an AR today...I settled on 16.7" from the glow plug to the High point on a Hatori 650, Turning 10,200 RPM's on a 12x12 APC, PowerMaster 20/20 fuel and an OS#8 plug...(Just breaking in)

Was running one of my std LS's Saturday and got the same length(16.7) on the Hatori 650...It's turning a 12x10 APC @ 10,300 RPM...

Some of threads I've researched recently the guys were running the Hatori 650's longer than that (17-20 inches) with the YS 61LS...

Sorry to contradict your expertise...I probably normally wouldn't ...But I just did it today...So I thought I'd share my experience...

Have Fun...

Chuck

P.S. I want a Summitt III also...

Thanks again for all the suggestions, guys. I guess I'll have to experiment with the various prop/pipe length combos to see what I really like. It did come with the Tru Turn spinner. The airplane is a taildragger and a 13" prop will just clear the ground when the tail raises. Do I have to retract the gear during a contest? I guess I could put bigger tires on to help with the ground clearance. It would also make it easier to operate from our grass club field. But of course, there is the drag penalty.

Also, I usually run OS #8 plugs, but some of your suggestions refer to other plugs. Are there more suitable plugs for this engine?

Is 10,000 RPM a minimum acceptable number givien the prop suggestions so far?

Bryan

No need to be sorry. As I mentioned earlier that's as close as I remember, 12-15 years ago. This is supposed to be educational forum and trying to get as much truth as possible....no contradiction present.

Having said that, there was a primary baffle approximately 2" aft of the high point, if memory serves. That placed the baffle approximately 17" aft of the plug. Are you measuring to the high point or to the baffle?

The high point was just a convenient way to measure. The baffle is the real desired measure. It's the reflector that causes resonance and hence the power boost.

Bryan, one simple way to check if your pipe is too long, put the model in a shallow 5 degree dive to unload it. If the engine goes fat, pipe is too long

MattK

Until a year ago I was using an older airplane with the YS .61 in it for competition. I started with 12x12 APC props on it turning around 9200 RPM on 10% nitro. Only problem with the 12x12 was that it never seemed to want to wind down for landing, so I went down to the 12x10. It turned slightly faster, gave better vertical performance, and slowed nicely for landing.

Gotcha...So actually I'm about 19.8" to the first baffle...I measured to the high point to get the 16.7 dimension...The First weld you see in the pipe is the first baffle which is 3.1" aft of the High Point...

I read your post earlier...Actually while I was running the engine I tried to go shorter...I could go a little...I know I'm a tiny bit conservative where I'm at...But I got a good needle adjustment...about 5 or 6 clicks between rich and lean...When I went more than .5" shorter...The needle began to get pretty sensitive...I don't really like that...I could pick up 100 or so RPM....But I just don't like that hypersensitive needle which is my first little indicator...I did cut the header down to 15.5 (to the high point) and that was too much for me...

I'm sure there will be some more fine tuning when I get these things airborne...All this was on the test stand...

But that is actually pretty consistent with what I had read in previous posts...I went back and re-read some of those comments...They were actually saying 20" to the first baffle rather than the "high point"...

And I'm sure My set-up will be different than Bryan's...But since I was right in the middle of the process as this came up...I thought I'd chime in...

Have Fun...

Chuck

Hey guys, I also have a summit III ready for paint and just received an OS61 and header but no pipe. What would you recommend for a pipe?

I Like Hatori Pipes...If you go to Tower Hobbies and search for "Hanno" a red anodized pipe should show up...I have read and reserched a bit on that pipe...I've convinced myself it's a Hatori #700 pipe which has had red anodizing applied...the Hatori 700 is a 10cc Long pipe and should be sutable for the OS RF's and YS 61 alike...But I have not tried it yet...

If you read the notes in Towers ad it will state something to the effect "specifically designed for the Hanno and don't use on a regular RF"... *I Personally* have decided that's a load of -------.... I could be wrong?? There are several threads where guys state about the same thing I'm thinking though...

Other thoughts I had were to check with ES and see if they had any pipes for these engines...I like Carbon Fiber!!

Hatori pipes #650 or #700 should be available from Singapore Hobbies...

Or there is Macs...

Congrats on the Summitt...I want one too!!

Have Fun...

Chuck

Thanks, I found the pipe here:
http://www3.towerhobbies.com/cgi-bin...?&I=LXCC49&P=7

I believe that the os61 I have is hanno modified....I'll have to check.

Yeah..That's exactly it...If the photo depicts the actual pipe...Then I believe it's a Hatori 700...If you see the picture in this thread of my AR on the test stand...The pipe in that picture is a Hatori 650...The 650 is a little shorter length (16.8" ) than the 700 (18-3/4" ) ...They are both 10cc pipes...

I have several pipes already...I was going to eventually get one of those from Tower but it's been sorta low on the priority list...If you get one I'd be curious to hear how it works out!!

I'd imagine the tuning dimensions will be a little different than the 650??

I like the Hatori pipes...They sound really good...

Have Fun...

Chuck